NESL TANKSWEEP is an innovative equipment for tank cleaning which allows the cleaning of hydrocarbon storage tanks with the recovery of a large amount of oil.

Applied at crude oil tank, this system guarantee the following advantages:

• Recovery of substantial quantities of oil which otherwise would be wasted
• Reduction of the volume of sludge for disposal and therefore reduction of the costs.
• Speed of operation; reducing down time for the tank.
• Safety: possibility of access via manholes on the tank, without the need to open the manholes, where there is a large amount of sludge; plus the non man entry.

Usually the heavy sludge deposited in tanks during many years of activity is composed by an high percentage of hydrocarbons.
The tanksweep system, eventually jointly with other Sepor’s equipments dedicated to the desludging and oil recovery, allow us to recover up to 95% of the hydrocarbons incorporated in the sludge.

Through the use of an infrared camera, our technicals will be able to monitor constantly the fluidization’s progress, to determine when the sludge has totally turned into a fluid and so, to judge when the process is over.

The infrared images are taken on the same point of the tank during different stage of the fluidization:
On the first imagine the colours are well merked the red area represent the sludge, the blue are is the gasoline supplied by the Refinery.
On the second imagine the colours are less defined: after 24 hr a large amount of sludge is broken and turned fluid.
On the third imagine, after 48 hr, the colour is only one: the sludge is almost turned into fluid.

The equipment is so composed:

• 2 to 4 hydraulic ejectors (ATEX zone 1 certified) installed into the oil tank shell through the manholes
• 2 to 4 motorpumps with the following performances: mc/h 700 with a pression of 11 bars

Two to four tanksweeps (depending on the tank’s size) are installed into the oil tank shell through the manholes and the motorpumps are positioned into the tank basin.
The tank has to be partially filled with gasoline or light oils (carrier) provided by the Client.
The rotative action of the whole system in about 3 – 4 days breaks the solid sludge and creates a liquid mix between the gasoline and the sludge.

Once Sepor technical staff will estabilish, with the help of an infrared camera, the good execution of the process and the total fludization of the tank’s content, the final step is to transfer of the floating oil to a storage facility provided by the client.
Finally after adequate ventilation and safety controls ensure that the tank is gas free, the remaining liquids are pumped out and the residual sediments are ready to be removed for disposal.